The overall objective of the proposed research continues to be to develop and use mass spectrometry as a tool for solving problems of biomedical interest, especially those dealing with the characterization of complex polar compounds and others of high molecular weight. The powerful research mass spectrometers--a VG 70-SE4F and a VG ZAB-SE--will be used in assigning structures to complex peptides and proteins: aldose reductases, cytochromes, marine-derived toxins, insect and marine invertebrate neuropeptides, marine algal and cyanobacterial GABA-mimetic peptides, and peptide antibiotics. The instruments will also be employed in improving or developing the FAB technique: by improving high-resolution FAB; by enhancing ion production with laser assistance; developing LC/HRMS and LC/MS/MS; and by applying LC/FAB to gradient elution HPLC and countercurrent chromatography (CCC). The mass spectrometric techniques developed will be applied to solving structural problems of the P.I. (antiviral and antitumor agents from marine sources, antibiotics, marine-derived chlorins, cyanobacterial toxins, a hibernation factor in bears' blood, hydroxamates from Hemophilus influenzae) and other biomedical scientists at the University of Illinois (i.a., methanogen cofactors, metallo-porphyrins, estrogen receptors, fluorinated steroids, viral proteins, phospholipids, glycolipids, and glycosphingolipids).